BitmapData::Scan0 Property
.NET Framework (current version)
Gets or sets the address of the first pixel data in the bitmap. This can also be thought of as the first scan line in the bitmap.
Assembly: System.Drawing (in System.Drawing.dll)
The following code example demonstrates how to use the PixelFormat, Height, Width, and Scan0 properties; the LockBits and UnlockBits methods; and the ImageLockMode enumeration. This example is designed to be used with Windows Forms. To run this example, paste it into a form and handle the form's Paint event by calling the LockUnlockBitsExample method, passing e as PaintEventArgs.
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The following example code was created for use with an image with the Format24bppRgb format. |
void LockUnlockBitsExample( PaintEventArgs^ e ) { // Create a new bitmap. Bitmap^ bmp = gcnew Bitmap( "c:\\fakePhoto.jpg" ); // Lock the bitmap's bits. Rectangle rect = Rectangle(0,0,bmp->Width,bmp->Height); System::Drawing::Imaging::BitmapData^ bmpData = bmp->LockBits( rect, System::Drawing::Imaging::ImageLockMode::ReadWrite, bmp->PixelFormat ); // Get the address of the first line. IntPtr ptr = bmpData->Scan0; // Declare an array to hold the bytes of the bitmap. // This code is specific to a bitmap with 24 bits per pixels. int bytes = Math::Abs(bmpData->Stride) * bmp->Height; array<Byte>^rgbValues = gcnew array<Byte>(bytes); // Copy the RGB values into the array. System::Runtime::InteropServices::Marshal::Copy( ptr, rgbValues, 0, bytes ); // Set every third value to 255. for ( int counter = 2; counter < rgbValues->Length; counter += 3 ) rgbValues[ counter ] = 255; // Copy the RGB values back to the bitmap System::Runtime::InteropServices::Marshal::Copy( rgbValues, 0, ptr, bytes ); // Unlock the bits. bmp->UnlockBits( bmpData ); // Draw the modified image. e->Graphics->DrawImage( bmp, 0, 150 ); }
.NET Framework
Available since 1.1
Available since 1.1
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